An Intramolecular Hydroaminomethylation-Based Approach to Pyrrolizidine Alkaloids under Microwave-Assisted Heating.

ABSTRACT: A general method for the synthesis of pyrrolizidine derivatives using an intramolecular hydroaminomethylation protocol (HAM) under microwave (MW) dielectric heating is reported. Starting from a 3,4-bis(benzyloxy)-2-[(benzyloxy)methyl]-5-vinylpyrrolidine, MW-assisted intramolecular HAM in the presence of gaseous H₂ and CO gave the natural alkaloid hyacinthacine A₂ protected as benzyl ether. The same approach gave a lentiginosine analogue starting from the corresponding vinyl N-hydroxypyrrolidine. The nature of the reaction products and the yields were strongly influenced by the relative stereochemistry of the starting pyrrolidines, as well as by the catalyst/ligand employed. The use of ethanol as a solvent provides environmentally friendly conditions, while the

SUBMITTER: Petricci E 

PROVIDER: S-EPMC9332719 | biostudies-literature | 2022 Jul

REPOSITORIES: biostudies-literature